QASPER: INSTRUCTIONS FOR USE · Imaging (MRI). It is a calibration standard for MRI based perfusion measurements using ASL. It simulates the process of delivery of arterial blood

GSP008 Issue B QASPER Instructions for Use 1 of 44

QASPER: INSTRUCTIONS FOR USE


REVISION HISTORY REVISION DESCRIPTION ISSUED BY DATE

A First draft release A Oliver-Taylor 25/01/2019

B Second draft release A Oliver-Taylor 08/07/2019

Contents Revision History .............................................................................................................................. 2

Figures ............................................................................................................................................ 4

Forward .......................................................................................................................................... 5

Declaration of Conformity ............................................................................................................... 5

Copyright Notice ............................................................................................................................. 5

Disclaimer ....................................................................................................................................... 5

Glossary and Abbreviations ............................................................................................................ 5

Quick Start Guide ........................................................................................................................... 7

About QASPER............................................................................................................................ 7

1 Introduction .............................................................................................................................. 8

1.1 About this book ................................................................................................................. 8

1.2 Identification ..................................................................................................................... 8

1.3 Manufacturer and Contact Information ............................................................................. 8

1.4 Entry into Service .............................................................................................................. 8

2 Intended users ......................................................................................................................... 9

2.1 Patient Population ............................................................................................................. 9

2.2 Special Skills, Training and Knowledge ............................................................................ 9

2.3 Maintenance Personnel .................................................................................................... 9

2.4 Service Personnel ............................................................................................................. 9

3 Scope of Use ......................................................................................................................... 10

4 Warnings, Cautions and Side-Effects ..................................................................................... 11

4.1 About Warnings and Cautions ........................................................................................ 11

4.2 Warnings ........................................................................................................................ 11

4.3 Cautions ......................................................................................................................... 11

5 Equipment Description .......................................................................................................... 13

5.1 About the Qasper System ............................................................................................... 13

5.1.1 GSP 1006 Phantom ................................................................................................. 14

5.1.2 GSP 1005 Power Supply .......................................................................................... 19

5.1.3 GSP 1015 Power Supply Unit Charger .................................................................... 20

5.1.4 GSP 1008 QASPER-LINK Wireless Interface ........................................................... 20


5.1.5 GSP 1018 QASPER-LINK Wireless Interface Charger and GSP 1014 QASPER-LINK

Wireless Interface Charger Cable .......................................................................................... 21

5.1.6 GSP 1026 QASPER-LINK USB Interface ................................................................. 22

5.1.7 Tuned Connection Cable ......................................................................................... 22

5.2 General Arrangement ..................................................................................................... 23

5.2.1 Communications Through Window .......................................................................... 24

5.2.2 Communications Through waveguide ..................................................................... 25

5.3 Controls and Indicators .................................................................................................. 26

5.3.1 GSP 1006 Phantom Pump Unit ................................................................................ 26

5.3.2 GSP 1005 Power Supply Unit .................................................................................. 26

5.3.3 GSP 1008 QASPER-LINK Wireless Interface ........................................................... 28

5.3.4 GSP 1026 USB Fibre Optic TRansceiver ................................................................. 29

5.3.5 GSP 1015 Power Supply Charger ............................................................................ 30

5.3.6 GSP 1018 QASPER-LINK Wireless Interface Charger ............................................. 30

6 Getting Started ...................................................................................................................... 31

6.1 Unpacking the Equipment .............................................................................................. 31

6.1.1 Lifting the Phantom .................................................................................................. 31

6.2 Before Use ...................................................................................................................... 32

6.3 Storage ........................................................................................................................... 32

6.4 Setting Up ....................................................................................................................... 33

6.4.1 Phantom placement ................................................................................................. 33

6.4.2 GSP 1005 Power supply Location ........................................................................... 34

6.4.3 GSP 1008 QASPER-LINK Wireless Interface Location ............................................. 34

7 Operating Instructions ........................................................................................................... 35

7.1 Switching On and Off ...................................................................................................... 35

7.1.1 Phantom .................................................................................................................. 35

7.1.2 Data communications .............................................................................................. 35

7.2 Built-in Test Facilities....................................................................................................... 35

7.3 Battery Recharging ......................................................................................................... 35

7.3.1 Power Supply .......................................................................................................... 35

7.3.2 QASPER-LINK Wireless Interface ............................................................................ 36

7.4 Separating the Pump and Perfusion Unit ........................................................................ 36

7.5 AIR Clearance ................................................................................................................ 38

7.6 QASPER Pump Control software ..................................................................................... 38

8 Using the QASPER System for ASL Quality Assurance Measurements ................................. 39

8.1 Recommended QASPER QA Protocol ............................................................................ 39

8.2 QASPER QA on GSP cloud............................................................................................. 40


8.3 Sources of Variability ...................................................................................................... 40

8.4 Equipment setup ............................................................................................................ 41

8.5 MRI Scan Planning ......................................................................................................... 42

9 MR Conditional statements .................................................................................................... 44

9.1 GSP 1006 Phantom ........................................................................................................ 44

9.2 GSP 1005 Power Supply ................................................................................................. 44

9.3 Tuned Connection Cable ................................................................................................ 44

9.4 GSP 1008 QASPER-LINK Wireless Interface .................................................................. 44

9.5 GSP 1019 Fibre Optic Cable .......................................................................................... 44

FIGURES Figure 1: The QASPER System ..................................................................................................... 13

Figure 2: GSP 1006 Phantom ........................................................................................................ 14

Figure 3: Phantom with Perfusion Unit and Pump Unit detached, ready to be scanned ............... 15

Figure 4: Perfusion Unit................................................................................................................. 15

Figure 5: Cross-section through the mid-plane of the of the PLC. ................................................. 16

Figure 6: Pump Unit. ..................................................................................................................... 17

Figure 7: Base split mechanism .................................................................................................... 17

Figure 8: Auto flow control algorithm ............................................................................................. 18

Figure 9: GSP 1005 Power Supply ................................................................................................ 19

Figure 10: GSP 1015 Power Supply Unit Charger ......................................................................... 20

Figure 11: QASPER-LINK Wireless Interface ................................................................................ 20

Figure 12: GSP 1018 QASPER-LINK Wireless Interface Charger and GSP 1014 QASPER-LINK Wireless Interface Charger Cable ................................................................................................. 21

Figure 13: GSP 1026 QASPER-LINK USB Interface ...................................................................... 22

Figure 14: QASPER Tuned Connection Cable ............................................................................... 22

Figure 15: Cable Trap Label ......................................................................................................... 23

Figure 16: GSP 1006 Phantom: Pump Unit, rear panel ................................................................. 26

Figure 17: GSP 1005 Power Supply, front panel ........................................................................... 26

Figure 18: GSP 1005 Power Supply Unit, rear panel ..................................................................... 27

Figure 19: GSP 1008 QASPER-LINK Wireless Interface, front panel ............................................. 28

Figure 20: GSP 1008 QASPER-LINK Wireless Interface, rear panel .............................................. 28

Figure 21: GSP 1026 QASPER-LINK USB Interface, fibre optic panel .......................................... 29

Figure 22: GSP 1026 QASPER-LINK USB Interface, USB panel ................................................... 29

Figure 23: GSP 1015 Power Supply Unit Charger, front panel ...................................................... 30

Figure 24: GSP 1018 QASPER-LINK Wireless Interface Charger, front panel ............................... 30

Figure 25: QASPER System in its Wheeled Transport Case .......................................................... 31

Figure 26: Phantom with Perfusion Unit and Pump Unit detached, ready to be scanned ............. 33

Figure 27: Using the laser marker to align in the L-R direction ...................................................... 33

Figure 28: How to separate the Pump Unit and Perfusion Unit using the Base Split Mechanism .. 37

Figure 29: Presence of air in the perfusion chamber..................................................................... 38

Figure 30: pCASL and PASL Labelling Strategies ......................................................................... 39

Figure 31: Standardised alignment of the QASPER phantom in a MRI scanner ............................ 42

Figure 32: FOV Placement. ........................................................................................................... 43


FORWARD The instructions for use contain all the information necessary to operate the QASPER system in

accordance with its specifications. This information includes explanations of the functions of the

controls, displays and signals, the sequence of operation, and connection and disconnection of

the parts and accessories you can remove.

You must regard these instructions as a part of the equipment. It is important that these

instructions are read thoroughly.

DECLARATION OF CONFORMITY

The QASPER System is in conformity with the essential requirements and provisions of:

• Medical Device Directive 93/42/EEC as amended 2007/47/EC, Class I.

• Machinery Directive 2006/42/EC as amended 2009/127/EC

• RoHS Directive 2011/65/EU

• Radio Equipment Directive 2014/53/EU

COPYRIGHT NOTICE Copyright © Gold Standard Phantoms Limited. 2019. ALL RIGHTS RESERVED

Registered trademarks are the intellectual property of their respective holders.

All rights reserved. No part of this book may be reproduced or copied in any form by any

graphic, electronic or mechanical means – including photocopying, scanning, typing or

information retrieval systems – without advanced written permission from Gold Standard

Phantoms.

DISCLAIMER Gold Standard Phantoms considers itself responsible for the effects on safety, reliability and

performance of the equipment only if:

• Assembly operations, re-adjustments, modification or repairs are carried out by persons

authorised by ourselves, and

• The electrical installation of the room where the device is used meets the requirements of

the standards in force, and

• The device is used in accordance with this book.

GLOSSARY AND ABBREVIATIONS

Term Description

QASPER Quantitative Arterial SPin labelling PErfusion

Reference MRI Magnetic Resonance Imaging ASL Arterial Spin Labelling SoC State of Charge (battery level in percent)


PLC Perfusion Labelling Chambers Perfusate The water-based liquid that circulates through

the QASPER system. USB Universal Serial Bus QA Quality Assurance

pCASL Pseudo Continuous Arterial Spin Labelling: a

labelling strategy that uses a rapid pulse train

to label inflowing blood at a plane. PASL Pulsed Arterial Spin Labelling: a labelling

strategy that uses a single inversion pulse to

label a bolus of blood. EPI Echo Planar Imaging: a rapid MRI image

acquisition technique 3D-GRASE 3D GRAdient and Spin Echo: A rapid MRI

image acquisition technique that combines

EPI and Fast Spin Echo pulse sequences that

can acquire an entire 3D volume in a single

shot. QUIPPSS/Q2TIPS Methods of truncating the labelled bolus for

PASL labelling, giving it a defined temporal

duration. TOF Time-of-Flight Angiogram: a MRI technique for

visualising the vasculature. FOV Field of View TE Echo Time TR Repeat Time T1 Spin-Lattice relaxation time T2 Spin-spin relaxation time


QUICK START GUIDE

ABOUT QASPER QASPER is a Perfusion Phantom for use with Arterial Spin Labelling (ASL) Magnetic Resonance

Imaging (MRI). It is a calibration standard for MRI based perfusion measurements using ASL. It

simulates the process of delivery of arterial blood to an organ in a controlled and reproducible

manner.

At the heart of the QASPER phantom is an MRI compatible pump that delivers a liquid at a

calibrated flow rate to a simulated capillary bed. During operation, fluid is pushed around a

closed system that is simply placed on the patient couch of an MRI scanner: it is not necessary to

put tubing through waveguides, or to empty and re-fill the system at each use. The phantom

continuously reports via wireless connection to a computer application its real-time operating

state such as flow rate, temperature, battery drain etc, and can also be controlled by the user for

example to set the flow rate set point to a specified value. The computer application provides an

intuitive graphical user interface for visualisation and control of the phantom, providing complete

control and assurance during image acquisition that the phantom is operating as intended.

Furthermore, data acquired of each phantom session can be saved for later comparison and

combined analysis with the imaging data.

So that quality assurance measurements can be made effectively, QASPER was designed to be

used with clinical ASL sequences and protocols. Computational fluid dynamics and numerical

tracer kinetics simulations were used to develop and design the flow path that the liquid takes,

ensuring that transit times and perfusion rates are in both the healthy and abnormal physiological

range.

The flow path within QASPER comprises of three compartments. The first simulates the feeding

arteries and arterioles that supply arterial blood to an organ. Vessel geometry and flow velocities

within this region match those found in the human body. Compartment two uses a porous

polymer substrate to simulate the microvascular, incoherent flow observed at the capillary bed.

The third compartment represents the remainder of the cardiovascular system; venous return from

the organ to the heart where it is pumped back. A deliberately long, labyrinthine flow path

ensures that none of the labelled bolus is recirculated before the label decays and ensures fully

developed equilibrium magnetisation.


1 INTRODUCTION

1.1 ABOUT THIS BOOK The purpose of this book is to promote the safe use of the QASPER system during its expected

service life. It describes the use of the device as intended by the manufacturer, and you should

regard it as part of the device.

This book gives instructions and information for healthcare professionals. It includes the details

necessary for you to brief other operators on the known contraindications to the use of the device,

and on the precautions to be taken.

Keep this book for future use. You can order replacement copies from Gold Standard Phantoms

during the expected life of the device, or alternatively download from

www.goldstandardphantoms.com.

1.2 IDENTIFICATION

WARNING 1. Do not make modifications to medical

equipment. This creates a risk to the patient

This book is only for the models and variants of the device listed in the table, and their approved

accessories.

Model Remarks

QASPER System 1.0.0 Manufactured from April 2018

1.3 MANUFACTURER AND CONTACT INFORMATION

The manufacturer of the QASPER system is Gold Standard Phantoms Limited. If you need help in

setting up, using or maintaining the QASPER system, or you wish to make a report of an

unexpected operation, tell the manufacturer at the address shown below.

Address Gold Standard Phantoms Limited

Unit 103 Belgravia Workshops

159-163 Marlborough Road

London

N19 4NF

United Kingdom

Telephone +44 (0) 207 684 7749

Email [email protected]

1.4 ENTRY INTO SERVICE The QASPER system must be put into service in accordance with the instructions in this book.

The device is for use within hospitals and imaging centres, especially in radiology departments.

http://www.goldstandardphantoms.com/


2 INTENDED USERS

2.1 PATIENT POPULATION The QASPER system is not designed to be used on or with patients. It is to be scanned on its

own.

2.2 SPECIAL SKILLS, TRAINING AND KNOWLEDGE The device must be used by a skilled person who has the applicable education and experience

to enable them to perceive risks and to avoid hazards which operation or maintenance of the

device can create.

The QASPER system must be operated by trained and competent personnel and used in

accordance with approved clinical practise.

Generally, it is expected that the QASPER system is set up by personnel who have training in

operating in and around the environment of an MRI scanner.

2.3 MAINTENANCE PERSONNEL The QASPER system requires preventative inspection and battery recharge after use. This should

be done by someone who has familiarised themselves with the instructions in this book, and who

are confident

2.4 SERVICE PERSONNEL The QASPER system can only be serviced by personnel authorised by Gold Standard Phantoms.


3 SCOPE OF USE The QASPER System is intended for use in conjunction with the following MRI systems, when

combined with the appropriate cable assembly:

Manufacturer Model Field Strength Compatible QASPER

Power Cable

Philips All models 1.5T GSP 1036

GE All models 1.5T GSP 1036

Siemens All models 1.5T GSP 1037

Siemens All models 3T GSP 1007

Philips All models 3T GSP 1021

GE All models 3T GSP 1021

Canon All models 3T GSP 1007

Philips All models 7T GSP 1034

GE All models 7T GSP 1034

Siemens All models 7T GSP 1035

If you wish to use the phantom with an MRI scanner that is not of the type listed above, please

contact Gold Standard Phantoms.


4 WARNINGS, CAUTIONS AND SIDE-EFFECTS Like other devices of this nature, the use of the QASPER system has inherent risks and side

effects. Whilst every effort has been taken to prevent these risks, be careful when using this

device

4.1 ABOUT WARNINGS AND CAUTIONS

A WARNING is given when the personal safety of the

patient or a user can be affected. Disregarding this

advice can cause an injury.

A CAUTION is given when special instructions must be

followed. Disregarding this advice can cause damage to

the device or other equipment.

To make sure that all users are satisfactorily informed, we have included warnings and cautions

throughout this book. This section gives warnings and cautions of a general nature. Additional

warnings and cautions appear with specific instructions and actions.

All users must familiarise themselves with all of the warnings and cautions contained in this book.

4.2 WARNINGS WARNING 1. Do not make modifications to medical equipment. This creates a risk to the patient

WARNING 2. Only the GSP 1015 Power Supply Unit Charger should be used to charge the GSP 1005 Power Supply. Do not use any other battery charger or AC-DC adapter. Doing so could

cause damage to the battery and may cause a fire.

WARNING 3. Before taking the transport case into the magnet room, remove the following MRI

Unsafe items: GSP 1015 Power Supply Charger, QASPER-LINK Wireless Interface Charger and

charging cable, GSP 1026 QASPER-LINK USB Interface, and USB Cable.

WARNING 4. Due to the size and weight of the GSP 1006 Phantom, only physically capable and

competent individuals should attempt to lift the Phantom on their own. Adhere to local manual

handling safety guidelines/rules. Gold Standard Phantoms accepts no liabilities for personal

injury, or damage that occurs to the QASPER system or other equipment when one person lifts

the phantom on their own.

WARNING 5. Before use, make sure all the functions of the device operate correctly. Also

examine the device and its accessories for any loose or damaged parts. Do not use the device if

there are loose or damaged parts.

WARNING 6. The Power Supply contains a li-ion battery that has a steel enclosure. DO NOT

bring the Power Supply any closer to the magnet once the magnetic field alarm sounds. Failing

to do this will pose a projectile hazard.

4.3 CAUTIONS CAUTION 1. Only use the GSP 1014 QASPER-LINK Wireless Interface Charger Cable to supply

power to the QASPER-LINK Wireless Interface

CAUTION 2. Before placing the phantom into the wheeled transport case, ensure that the antenna

at the rear of the Pump Unit is correctly folded. Failure to do so will result in it being caught in the

case, damaging the antenna and other components in the Pump Unit. CAUTION 3. Do not automatically move the Phantom to/from isocentre. If this is done without any

means to restrain the Pump Unit, it will be moved by the Lorentz force it experiences. If the


restraining tethers between the Pump Unit and Perfusion Units become taught this could result in

the Perfusion Unit being moved (and thus losing alignment).

CAUTION 4. The Tuned Connection Cable can only be connected in one orientation. The short

end connects to the Pump Unit, and the long end to the Power Supply. Do not try to connect the

other way round: this will damage the connectors and sockets.

CAUTION 5. Ensure that the GSP 1005 Power Supply is switched OFF when not in use. Failure to

do so will result in the battery becoming over-discharged.

CAUTION 6. If the Power Supply battery becomes over-discharged to the point where the internal

cut-off circuitry is activated, the Power Supply Charger will not be able to successfully charge the

battery. If this occurs, please contact Gold Standard Phantoms. To avoid this from happening

ensure that the Power Supply is recharged after each use, and if not used for a long period of

time, ensure that it is checked and recharged every month.

CAUTION 7. Ensure that the base is correctly locked together before attempting to lift the

Phantom. Failure to do so could result in the two parts becoming separated, potentially resulting

the Phantom being dropped and damaged.


5 EQUIPMENT DESCRIPTION

5.1 ABOUT THE QASPER SYSTEM

The QASPER System consists of the following components:

ID Name

GSP 1006 Phantom

GSP 1005 Power Supply Unit

GSP 1008 QASPER-LINK Wireless Interface

GSP 1026 QASPER-LINK USB Interface

GSP 1007 Tuned Connection Cable (Siemens/Canon 3T)

GSP 1021 Tuned Connection Cable (Philips/GE 3T)

GSP 1034 Tuned Connection Cable (Philips/GE 7T)

GSP 1035 Tuned Connection Cable (Siemens 7T)

GSP 1036 Tuned Connection Cable (Philips/GE 1.5T)

GSP 1037 Tuned Connection Cable (Siemens 1.5T)

GSP 1019 Fibre Optic Data Cable

GSP 1015 Power Supply Charger

GSP 1018 QASPER-LINK Wireless Interface Charger

GSP 1014 QASPER-LINK Wireless Interface Charging Cable

During normal operation the Phantom is placed on the patient couch of the MRI scanner, with the

head section located within a head coil. A liquid, hereafter referred to as the perfusate is pumped

in a highly controlled manner to the head section where it passes through a porous polymer

substrate that simulates the capillary bed. The Phantom is powered by the Power Supply, which

connects via a cable loom. The Tuned Connection Cable used must be matched to the type of

MRI scanner being used in conjunction with the QASPER system. Additional cable looms are

available as a purchasable accessory from Gold Standard Phantoms.

Figure 1: The QASPER System


The Phantom makes a wireless connection to the QASPER-LINK Wireless Interface, enabling

remote control of the flow rate that the perfusate is pumped at, and real-time telemetry of the

Phantom’s operating conditions. The QASPER-LINK Wireless Interface is located within the MRI

scan room.

Data is sent in/out of the magnet room via the Fibre Optic Cable. The QASPER-LINK USB Interface is located next to the host control computer to an interface between the fibre optic and

USB data.

The QASPER system will function without the presence of a host computer. Under these

conditions the flow rate will be set at its default rate (350ml/min), and a LED will be lit when this

flow rate is being achieved.

The constituent components will now be described in further detail.

5.1.1 GSP 1006 PHANTOM

The Phantom comprises of two units, the Perfusion Unit and Pump Unit. They are fixed together

using a latch mechanism. They should be locked together when lifting the Phantom, and during

transport within the Wheeled Transport Case. When placed on the patient couch of the MRI

scanner, the lever slides across to disengage the latch, and the Perfusion Unit and Pump Unit moved apart. This means the pump can be located outside of the gradient coil’s field, mitigating

the induction of gradient induced eddy-currents into the system, which can affect the flow

measurement and can also cause motion artefacts in the Perfusion Unit.

Figure 2: GSP 1006 Phantom


5.1.1.1 PERFUSION UNIT

The Perfusion Unit contains the Perfusion and Labelling Chambers (PLC) at the “head” end. This

is where the ASL labelling and imaging takes place. In addition, there are two bubble traps and a

coiled hose reservoir. The coiled hose reservoir slows down the transit of perfusate around the

circuit so that it takes approximately two minutes, ensuring there is fully developed equilibrium

magnetisation, and preventing the recirculation of any labelled perfusate.

Figure 3: Phantom with Perfusion Unit and Pump Unit detached, ready to be scanned

Figure 4: Perfusion Unit


The labelling chamber mimics a neck and contains a single 6mm diameter “artery” through which

perfusate flows, surrounded by static perfusate. At a flow rate of 350ml/min the velocity of the

perfusate as it travels through this tube is approximately 20/40 cm/s (mean/peak)1.

After the labelling chamber, the perfusate flows into a branching region, where it splits into sixty

1mm wide channels that travel radially in the axial plane, before turning 90º to run axially into the

perfusion chamber via 1mm diameter “arteriole” holes. The dimensions and arrangement of this

branching region has been optimised to ensure that the transit time is equivalent to the transit

time in adult humans (0.5-1.5s1).

The perfusion chamber contains six 4.75mm thick, 116mm diameter discs of porous UHMW-PE2,

which simulate the capillary bed of an organ. The 1mm arterioles extend into the first two layers

of the material. Perfusate is delivered via these holes into the perfusion matrix material, where

once inside it slowly (1-2mm/s, dependent on flow rate) travels through to the periphery of the

perfusion chamber. Perfusate then exits via an axially located hole at the distal end of the

perfusion chamber, returning to the pump.

The interface plane between layers 3 and 4 of the porous stack defines the mid-point of the

perfusion chamber. When scanning, it is recommended that this location is used as the centre of

the imaging field of view (FOV). Fiducial markers within the labelling chamber define fixed offsets

for the label plane location. The first marker is at a distance of 50mm, and subsequent markers at

1 At the default system flow rate of 350ml/min. 2 Pore sizes ranging from 3-30um, with mean pore size 7um.

Figure 5: Cross-section through the mid-plane of the of the PLC.

All dimensions are in millimetres.


10mm intervals up to 150mm from the centre of the porous stack.

There are two bubble traps in the system, located before the PLC, and after the reservoir.

Bubbles flowing within the system are caught in the bubble traps, preventing them from entering

either the PLC or pump.

The reservoir consists of a long length of coiled tubing. Its purpose is to extend the perfusate

circulation time to two minutes1 ensuring that fully-developed equilibrium magnetisation enters the

PLC, and preventing the recirculation of any labelled perfusate before the label has time to fully

decay.

5.1.1.2 PUMP UNIT

The Pump Unit delivers continuous flow at a controlled rate to the perfusion unit. It uses

piezoelectrically operated diaphragm pumps, which are completely MRI compatible as they

contain no ferromagnetic material and generate for electro-magnetic interference. A calibrated

Figure 6: Pump Unit.

Figure 7: Base split mechanism


flow meter and microcontroller-based system actively controls the flow rate during operation. The

workings of the Pump Unit are housed in an aluminium enclosure that is electromagnetically

shielded, preventing interference between the MRI scanner and the housed circuitry.

To minimise the induction of gradient eddy currents and subsequent vibrations, and prevent

transmission of these to the PLC, the Pump Unit and Perfusion Unit are mechanically decoupled

using a latch mechanism. This consists of three attachment bosses that are secured by a sliding

latch that is located on the Perfusion Unit.

5.1.1.3 FLOW CONTROL

Active, closed-loop flow control ensures that the same perfusate flow rate is achieved in the

system over a wide range of operating conditions. The piezoelectric pumps are driven by high

voltage sinusoidal waveforms, and the perfusate flow rate is governed by this amplitude. A

calibrated optical turbine flow meter continuously measures the system flow rate, and this

information is used by a 32-bit ARM microcontroller to adjust the piezoelectric pump waveform

amplitude using a proportional-integral-derivative (PID) algorithm so that the desired flow rate is

achieved. Due to the intrinsic noise in the flow measurement and the oscillating nature of PID

based controllers, the actual flow rate will fluctuate, typically by a few percent of the desired

value. Note that at high flow rates (>400-450ml/min) the increase in system pressure due to the

resistance in the porous material means that pulsations from the piezoelectric pumps are less

effectively dampened, and as a result the flow measurement and subsequent flow stability will

have more fluctuations (as much as 10%). This is normal.

There is an upper flow rate limit, governed by the maximum amplitude that the piezoelectric

pumps can be driven at. Because the achieved flow rate is highly dependent on factors such as

temperature, this upper limit will vary, but usually should be 450ml/min or greater. Always check

that the desired flow rate is achieved, if the piezoelectric pump amplitude is 1.0 then this is

unlikely.

5.1.1.4 DATA COMMUNICATIONS

The pump unit continuously measures the perfusate flow rate and temperature. These values, as

well as operating parameters are sent via a wireless and fibre optic link to a host computer

running the QASPER Pump Control Software.

Piezoelectric

Pump Amplitude

Flow Meter

Desired

Flow Rate

Perfusate

Flow

Figure 8: Auto flow control algorithm


5.1.2 GSP 1005 POWER SUPPLY

The GSP 1005 Power Supply provides low and high voltage power to the GSP 1006 Phantom.

This is because the piezoelectrically operated diaphragm pumps located in the Pump Unit require

a high voltage waveform to actuate them. Ferromagnetic components are used to generate the

high voltages (+150V and -150V) from a low voltage battery. However, these components will not

function if there is excessive ambient magnetic field, so a separate power supply is required that

can be located away from the MRI scanner. The power supply has the following features:

• Contains a 11.1V, 2400mAh lithium ion battery, providing approximately 2 hours of

phantom use per charge.

• Monitors the high and low voltages delivered to the phantom.

• Communicates with the phantom, reporting parameters such as the battery level.

• Magnetic field sensor and alarm function: continuously monitors the magnetic field and

sounds an alarm if the ambient magnetic field exceeds approximately 32mT.

• LED indication of the battery state of charge.

The Power Supply is to be used within the MRI scan room, located towards the edges of the room,

where the ambient magnetic field is less than approximately 32mT.

It is not possible to charge the Power Supply and power the Phantom at the same time. To extend

the operating time of the QASPER system please purchase additional Power Supply Kits from

Gold Standard Phantoms.

The power supply will supply high voltages to the phantom until the battery state of charge

reaches 5%, at this point they will be turned off and fluid will no longer be pumped around the

phantom system.

Figure 9: GSP 1005 Power Supply


5.1.3 GSP 1015 POWER SUPPLY UNIT CHARGER

The GSP 1015 Power Supply Unit Charger is used to charge the lithium-ion battery contained within

the GSP 1005 Power Supply. Only this charger should be used to charge the battery. It comes

supplied with a plug for the specific locale the QASPER system was sold to (e.g. UK, EU, USA, AUS

etc).

WARNING 2. Only the GSP 1015 Power Supply Unit Charger should be used to

charge the GSP 1005 Power Supply. Do not use any other battery charger or

AC-DC adapter. Doing so could cause damage to the battery and may cause a

fire.

5.1.4 GSP 1008 QASPER-LINK WIRELESS INTERFACE

The GSP 1008 QASPER-LINK Wireless Interface initiates a wireless connection to the Phantom,

and converts data sent/received to a fibre optic data link. Each QASPER-LINK Wireless Interface

is paired for use with a specific GSP 1006 Phantom, and this is indicated on a label on the

underside of the QASPER-LINK Wireless Interface.

The QASPER-LINK Wireless Interface has the following features:

Figure 10: GSP 1015 Power Supply Unit Charger

Figure 11: QASPER-LINK Wireless Interface


• Automatically initiates a wireless connection to the paired Phantom3.

• LED indication of the wireless connection status.

• LED indication of the battery state of charge.

• Battery operated with a 3.7V lithium-polymer battery life. Battery life greater than 10 hours.

• Can be powered/charged directly from a USB connection, or the supplied QASPER-LINK

Wireless Interface charger.

5.1.5 GSP 1018 QASPER-LINK WIRELESS INTERFACE CHARGER AND GSP 1014 QASPER-LINK WIRELESS INTERFACE CHARGER CABLE

The GSP 1018 QASPER-LINK Wireless Interface Charger is an AC-DC adapter that supplies 5V

over a USB port. The GSP 1014 QASPER-LINK Wireless Interface Charger Cable connects

between the USB socket on the charger and the power-in socket on the QASPER-LINK Wireless Interface.

CAUTION 1. Only use the GSP 1014 QASPER-LINK Wireless Interface Charger Cable to supply power to the QASPER-LINK Wireless Interface

3 Multiple QASPER-LINK Wireless Interfaces can be paired to the same Phantom.

Figure 12: GSP 1018 QASPER-LINK Wireless Interface Charger and GSP 1014 QASPER-LINK Wireless Interface Charger Cable


5.1.6 GSP 1026 QASPER-LINK USB INTERFACE

The GSP 1026 QASPER-LINK USB Interface connects between a host computer and the fibre

optic data link. Powered by the USB connection to the computer, it converts optical data to a

virtual com port (VCP), which appears as a serial COM port on a Windows computer. A driver

may be required for the host computer, this can be downloaded from

https://www.ftdichip.com/Drivers/CDM/CDM21228_Setup.zip

5.1.7 TUNED CONNECTION CABLE

The Tuned Connection Cable connects between the GSP 1005 Power Supply Unit and the GSP

1006 Phantom. It carries both low and high voltage power to the phantom, and low-speed

communications between the two devices.

A tuned cable trap is mounted on the QASPER Tuned Connection Cable to prevent radio

frequency interference with the MRI scanner. Its tuned frequency should match the MRI

scanners’. As such there are multiple versions of the Tuned Connection Cable:

Figure 13: GSP 1026 QASPER-LINK

USB Interface

Figure 14: QASPER Tuned Connection Cable


ID Compatible MRI System

GSP 1007 Siemens/Canon 3T (123.2 MHz)

GSP 1021 Philips/GE 3T (127.7 MHz)

GSP 1034 Philips/GE 7T (298.0 MHz)

GSP 1035 Siemens 7T (297.2 MHz)

GSP 1036 Philips/GE 1.5T (63.9 MHz)

GSP 1037 Siemens 1.5T (63.3 MHz)

The model and compatible MRI scanners is indicated on the label on the cable trap, as shown in

Figure 15.

The Tuned Connection Cable can only be connected in one orientation. The short length of cable

(~30cm) after the cable trap has a six-pin connector that mates with a socket in the Pump Unit. The long length of cable (>4.5m) has an eight-pin connector that mates with a socket in the Power Supply.

The 7T versions of the cables are approximately 10m in length, providing extra distance in the

case of unshielded magnets.

5.2 GENERAL ARRANGEMENT The general arrangement of the QASPER system is as follows:

The Phantom is placed on the patient couch of an MRI scanner, with the PLC located inside the

head coil. The latch mechanism is disengaged, and the Pump Unit positioned at its maximum

distance away from the Perfusion Unit so that the tethers are taught. The Power Supply is

connected to the Phantom via the Tuned Connection Table, and then switched on. The pump will

start, and after a short stabilisation period, perfusate will be pumped around the phantom at the

default flow rate (350ml/min).

If a paired QASPER-LINK Wireless Interface is brought into communications range with the

Phantom and switched on, a wireless connection will automatically be established between the

Phantom and QASPER-LINK Wireless Interface. The QASPER-LINK Wireless Interface then

connects via fibre optic cable to the QASPER-LINK USB Interface, which connects to a computer

by USB so that the QASPER Control Software can monitor and control the Phantom.

There are two ways that the data communications equipment can be arranged. If there is a

window into the MRI scan room, it is possible that the wireless connection between the Phantom

Figure 15: Cable Trap Label


and QASPER-LINK Wireless Interface will operate through the window. Alternatively, the

QASPER-LINK Wireless Interface can be left in the MRI scan room, and a fibre optic cable run

through a waveguide. The two techniques are summarised in the table below:

Communications through

window Communications through waveguide

Requirements Window in the MRI scan room

that does not shield 2.4GHz.

Accessible waveguide in the

MRI scan room. Ease of setup Easy Depends on how accessible

the waveguide is. Advantages Quick to set up Connection is not dependent

on wireless performance

through the window. Disadvantages The wireless signal may not

be strong enough if the

room’s shielding is particularly

effective, or if there is no

direct line of sight between

the scanner bore and the

window.

The supplied fibre optic cable

is only 5 metres long.

5.2.1 COMMUNICATIONS THROUGH WINDOW

The QASPER-LINK wireless communications operate at 2.4GHz. Because an MRI scan room only

needs to have effective shielding close to the operating frequency of the MRI scanner, in many

cases it is possible that this wireless connection can be established through a window. To do so

the QASPER-LINK Wireless Interface should be positioned close to the window on the outside of

the magnet room (if there is a ledge or windowsill this is ideal). The fibre optic cable then

connects between the QASPER-LINK Wireless Interface and QASPER-LINK USB Interface, which

connects by USB to the control computer.


This is the recommended method for communications and should be attempted first. Note that a

wireless connection may be established (i.e. the QASPER-LINK Wireless Interface connection

LED is green), but data throughput too low to be able to reliably receive streamed data using the

QASPER pump control software. If the data plotting stutters, or there are gaps in the received

data then the connection through the window is sub-optimal, and the waveguide method should

be used.

5.2.2 COMMUNICATIONS THROUGH WAVEGUIDE

The fibre optic cable can also be run through a waveguide from the magnet room to the control

room. The cable can either be left permanently or removed each time. In this configuration, the

QASPER-LINK Wireless Interface should be located within the magnet room, close to the

waveguide. The supplied fibre optic cable is 5m in length, if a longer cable is required please

contact Gold Standard Phantoms.


5.3 CONTROLS AND INDICATORS

5.3.1 GSP 1006 PHANTOM PUMP UNIT

ID Name Type Description

1. Fault LED Red LED Lit if there is a fault

2. Flow LED Green LED

Indicates whether the pump is on,

and the state of the auto flow control.

Flow Flow

Control

Flow Rate Met

LED Code

✓ ✓ 5Hz

Flash

✓ ✓ ✓ On

✓ 1Hz

Flash

Off

3. Connection LED Bi-colour

Red/Green LED

Indicates the status of the wireless

Connection: Mode LED Code

Waiting for

connection

Red and

Green LEDs

alternately

flashing

Connected Green On

Fault Red On

4. Power Socket 6-Pin Socket Mates with QASPER Power Cable

5.3.2 GSP 1005 POWER SUPPLY UNIT

1.

2.

3.

5.

4.

Figure 17: GSP 1005 Power Supply, front panel

1.

2.

3.

4.

Figure 16: GSP 1006 Phantom: Pump Unit, rear panel



1. Field LED Red LED

Flashes at a rate proportional to the

measured ambient magnetic field.

Solidly lit when the field exceeds 32mT

2. HV LED Green LED

Indicates if the high voltages are

supplied to the Phantom. Mode LED Code

High Voltages

On On

High Voltages

Off Off

3. Power LED Green LED

Indicates if the Power Supply Unit is on

or off. Mode LED Code

Power Supply

On On

Power Supply

Off Off

4. Battery SoC Switch Momentary

sliding switch

Slide to the left to illuminate the Battery

SoC LED Array

5. Battery SoC Array LED Array

Displays the battery SoC level: LED (left to right) Lit Condition

Red SoC > 0%

Yellow SoC > 20%

Yellow SoC > 40%

Green SoC > 60%

Green SoC > 80%


1. On/Off Switch Slide Switch Turns the Power Supply On (left) and

Off (right)

2. Power Socket 8-Pin Socket Mates with the QASPER Power Cable,

or GSP 1015 Power Supply Charger

1. 2.

Figure 18: GSP 1005 Power Supply Unit, rear panel


5.3.3 GSP 1008 QASPER-LINK WIRELESS INTERFACE


1. Power In LED Red LED

Indicates whether a valid 5V power

source is present at the power socket. Mode LED Code

Power input

present On

Power input not

present Off

2. Battery Charging LED Red LED

Indicates if the internal battery is being

charged Mode LED Code

Battery

Charging On

Battery not

charging Off

3. Connection LED Bi-colour

Red/Green LED

Indicates the status of the wireless

connection: Mode LED Code

Waiting for

connection

Red and

Green LEDs

alternately

flashing

Connected Green On

Fault Red On

4. Battery SoC Switch Momentary

sliding switch

Slide to the left to illuminate the Battery

SoC LED Array

5. Battery SoC Array LED Array

Displays the battery SoC level: LED (left to right) Lit Condition

Red SoC > 0%

Yellow SoC > 25%

Green SoC > 50%

Green SoC > 75%


1. Power Socket 8-Pin Socket

Mates with the GSP 1014 QASPER-LINK Wireless Interface Charging

Cable

2. On/Off Switch Slide Switch Turns the QASPER-LINK Wireless Interface On (right) and Off (left)

1.

2.

3.

4.

5.

Figure 19: GSP 1008 QASPER-LINK Wireless Interface, front panel

2.

1.

3.

4.

5.

Figure 20: GSP 1008 QASPER-LINK Wireless Interface, rear panel


3. Antenna Socket Coaxial Socket

The QASPER-LINK Wireless Interface

antenna screws on here. This is

normally attached permanently.

4. FO-Receive Fibre Optic

Receiver Receives optical data

5. FO-Transmit Fibre Optic

Transmitter Transmits optical data

Note: silicone plugs are supplied for the fibre optic transmit and receive ports, these should be

inserted when the unit is not in use to prevent the ingress of dust that may degrade performance.

5.3.4 GSP 1026 USB FIBRE OPTIC TRANSCEIVER


1. Transmit LED Red LED

Indicates data is being transmitted. Mode LED Code

Data

transmitting On

Idle Off

2. Receive LED Red LED

Indicates data is being received Mode LED Code

Data received On

Idle Off

3. FO-Receive Fibre Optic

Receiver Receives optical data

4. FO-Transmit Fibre Optic

Transmitter Transmits optical data


1. Power LED Red LED

Indicates the QASPER-LINK USB Interface is on.

Mode LED Code

Power On On

Power Off Off

2. USB USB B Socket USB cable mates with this socket

1.

2.

3.

4.

Figure 21: GSP 1026 QASPER-LINK USB Interface, fibre optic panel

1.

2.

Figure 22: GSP 1026 QASPER-LINK USB Interface, USB panel


5.3.5 GSP 1015 POWER SUPPLY CHARGER


1. Error LED Red LED

Indicates if there is an error. Mode LED Code

Charge Error Flash 2Hz

Charge OK Off

2. Charge/Ready LED Green LED

Indicates the charging status Mode LED Code

Charging Flash 1Hz

Charge

Complete On

Not charging Off

5.3.6 GSP 1018 QASPER-LINK WIRELESS INTERFACE CHARGER


1. Power LED Orange LED

Indicates if the charger is powered. Mode LED Code

Charger On On

Charger Off Off

1.

2.

Figure 23: GSP 1015 Power Supply Unit Charger, front panel

1.

Figure 24: GSP 1018 QASPER-LINK Wireless Interface Charger, front panel


6 GETTING STARTED

6.1 UNPACKING THE EQUIPMENT

The QASPER system is transported and stored within a Wheeled Transport Case. The case itself

is mostly made from plastic, however a small number of parts are stainless steel. It can be safely

brought into the MRI scan room of a 3T or 1.5T magnet, so long as it is kept at the edges of the

room, in the same locations that the Power Supply can safely operate.

WARNING 3. Before taking the transport case into the magnet room, remove the following MRI Unsafe items: GSP 1015 Power Supply Charger, QASPER-LINK Wireless Interface Charger and charging cable, GSP 1026 QASPER-LINK USB Interface, and USB Cable.

The transport case is intended to last for the service life of the device.

• The weight of the case with its contents is approximately 35kg.

• The outside of the box carries information to identify the device and to show the conditions

for transport and storage.

Keep the transport case, to hold the QASPER system with its accessories when the device is not

in use, or stored, or returned for servicing.

6.1.1 LIFTING THE PHANTOM The Phantom weighs approximately 12kg, and has four handles, two on the Perfusion Unit (orange) and two on the Pump Unit (blue). It is designed be lifted by either one or two people.

Figure 25: QASPER System in its Wheeled Transport Case


6.1.1.1 ONE PERSON LIFT

WARNING 4. Due to the size and weight of the GSP 1006 Phantom, only

physically capable and competent individuals should attempt to lift the Phantom

on their own. Adhere to local manual handling safety guidelines/rules. Gold

Standard Phantoms accepts no liabilities for personal injury, or damage that

occurs to the QASPER system or other equipment when one person lifts the

phantom on their own.

For one person to lift the phantom, one orange and one blue handle should be used. Lift the

phantom using these handles, taking care to ensure that the Phantom remains flat.

6.1.1.2 TWO PERSON LIFT

Person A should lift using the two orange handles. Person B should lift using the two blue

handles. During lifting ensure that the Phantom remains flat.

6.2 BEFORE USE

WARNING 5. Before use, make sure all the functions of the device operate

correctly. Also examine the device and its accessories for any loose or

damaged parts. Do not use the device if there are loose or damaged parts.

Each time before use, ensure the following

1. The Power Supply and QASPER-LINK Wireless Interface have sufficient charge. Please

see section 7.3 for the charging procedure.

2. Check the system for any signs of damage.

3. Clear any bubbles that are present in the perfusion chamber. Please see section 7.5 for

this procedure.

6.3 STORAGE It is recommended that the phantom is stored in the MRI scan room when not in use, ensuring that

the phantom is in thermal equilibrium and preventing exposure to temperature extremes. The

phantom can be stored either inside, or outside of the wheeled transport case.

CAUTION 2. Before placing the phantom into the wheeled transport case, ensure

that the antenna at the rear of the Pump Unit is correctly folded. Failure to do so

will result in it being caught in the case, damaging the antenna and other

components in the Pump Unit.

Storage guidelines:

• Ensure that the Power Supply and QASPER-LINK Wireless Interface are switched OFF

after use. Failure to do so will result in flat batteries (see section 7.3).

• On a weekly basis ensure that the Phantom’s pump runs for at least 5 minutes. This

ensures that the perfusate stays well mixed.

• On a weekly basis check the battery levels and recharge as necessary.

• Store at a temperature between 15°C and 30°C (ideally at 20°C).


6.4 SETTING UP

6.4.1 PHANTOM PLACEMENT

1. The phantom should be placed on the patient couch so that the PLC is located in the head

coil.

2. The antenna at the rear of the Pump Unit should be oriented either horizontally or vertically

as shown in Figure 26.

3. The base split mechanism should be disengaged, and the Pump Unit moved to its full

extent away from the Perfusion Unit. 4. If necessary, use foam padding/sandbags to raise the height of the Perfusion Unit so that

it can be optimally placed in the head coil.

5. Use the laser market along the top of the PLC to align the Perfusion Unit in the L-R

direction.

6. AP/HF alignment can be done either visually, or with a small plastic spirit level (not

supplied).

Figure 26: Phantom with Perfusion Unit and Pump Unit detached, ready to be scanned

Figure 27: Using the laser marker to align in the L-R direction


7. Manually move the phantom to isocentre: the aluminium pump box will experience a

lorentz force that opposes motion, causing it to pull away from the Perfusion Unit. This can

be avoided by firmly pressing the pump enclosure down onto the patient couch during

motion.

CAUTION 3. Do not automatically move the Phantom to/from isocentre. If this is

done without any means to restrain the Pump Unit, it will be moved by the

Lorentz force it experiences. If the restraining tethers between the Pump Unit and Perfusion Units become taught this could result in the Perfusion Unit being

moved (and thus losing alignment).

6.4.2 GSP 1005 POWER SUPPLY LOCATION The Power Supply should be located within the magnet room, in a location where the ambient

magnetic field is below 32mT. The Power Supply has a built-in magnetic field sensor and alarm

that will sound if it exceeds this limit. Typically, locations at the edges of the magnet room, off

axis, and low down on the floor will be well below this.

To establish a safe location, first turn the Power Supply on before entering the magnet room. A

beep will sound briefly. Enter the magnet room, and locate the Power Supply in a suitable

location, ensuring that the device does not alarm.

If the Power Supply does produce a beep, immediately move further away from the magnet.

WARNING 6. The Power Supply contains a li-ion battery that has a steel

enclosure. DO NOT bring the Power Supply any closer to the magnet once the

magnetic field alarm sounds. Failing to do this will pose a projectile hazard.

Once a suitable location has been found, connect the Phantom to the Power Supply using the

Tuned Connection Cable.

CAUTION 4. The Tuned Connection Cable can only be connected in one

orientation. The short end connects to the Pump Unit, and the long end to the

Power Supply. Do not try to connect the other way round: this will damage the

connectors and sockets.

6.4.3 GSP 1008 QASPER-LINK WIRELESS INTERFACE LOCATION There are two options for the QASPER-LINK Wireless Interface, depending on the

communications configuration (see section 5.2 for more information).

For communications through the window, the QASPER-LINK Wireless Interface is best located

close to the console room window, however any location that has acceptable wireless reception is

acceptable. In this configuration it is also possible to power/charge the QASPER-LINK Wireless Interface whilst using it, as the QASPER-LINK Wireless Interface Charger can be used outside of

the magnet room.

For waveguide communications the QASPER-LINK Wireless Interface is located within the magnet

room, normally close to an available waveguide. Because the QASPER-LINK Wireless Interface

charger is MRI Unsafe it cannot be taken into the magnet room, therefore ensure that the

QASPER-LINK Wireless Interface has sufficient charge before using.


7 OPERATING INSTRUCTIONS

7.1 SWITCHING ON AND OFF

7.1.1 PHANTOM 1. Connect the Tuned Connection Cable between the Power Supply and Phantom.

2. Slide the on/off switch on the Power Supply to the on position.

3. After a couple of seconds, the pump will start, the LEDs on the panel on the Pump Unit will

be lit, and an audible hum will be heard indicating the fluid is being pumped.

4. The pump will always start with a default flow rate of 350ml/min. If this flow rate is being

met then the flow LED at the rear of the Pump Unit will be lit green.

To turn off reverse these steps. Ensure that the Power Supply is turned off after use.

CAUTION 5. Ensure that the GSP 1005 Power Supply is switched OFF when not

in use. Failure to do so will result in the battery becoming over-discharged.

7.1.2 DATA COMMUNICATIONS These instructions assume that the Phantom is switched on.

1. Connect the QASPER-LINK USB Interface to a host computer using the USB A-B cable.

2. Connect the QASPER-LINK USB Interface to the QASPER-LINK Wireless Interface using

the fibre optic cable.

3. Slide the on/off switch on the QASPER-LINK Wireless Interface to the on position.

4. Wait for the QASPER-LINK Wireless Interface and Phantom to initiate a wireless connection

(both connection LEDs will be lit solid green once the connection is established).

5. Start the QASPER Pump Control software on the host computer and connect to the

phantom. Follow the instructions in the QASPER Pump Control software manual for further

details.

To turn of reverse these steps. Ensure that the QASPER-LINK Wireless Interface is turned off after

use.

7.2 BUILT-IN TEST FACILITIES Both the GSP 1005 Power Supply and GSP 1008 QASPER-LINK Wireless Interface contain built-in

test facilities to check the battery state of charge. This is achieved by sliding the Battery SoC

switches on either device, resulting in the Battery SoC LED arrays being lit. Operation is identical

on both devices, however:

• Power Supply: This feature can be operated regardless of whether unit is powered or not.

• QASPER-LINK Wireless Interface: This feature can only be operated when the unit is

powered.

7.3 BATTERY RECHARGING The Power Supply and QASPER-LINK Wireless Interface both contain batteries. These must be

recharged between use.

7.3.1 POWER SUPPLY The Power Supply is charged using the GSP 1015 Power Supply Charger. To charge:

1. Ensure that the Power Supply is off.


2. Plug the Power Supply Unit Charger into a power outlet socket.

3. Plug the charge cable into the Power Socket on the Power Supply.

The full charge will take approximately 5-6 hours. During charging the Charge/Ready LED on the

Power Supply Charger will flash green and will be lit solidly when charging is complete.

To prevent over-discharge of the battery, the Power Supply Unit will not allow the pump to run if

the battery is less than 5%. When this happens please stop using the QASPER system and

charge the power supply as soon as possible. This will prevent the risk of over-discharge.

CAUTION 6. If the Power Supply battery becomes over-discharged to the point

where the internal cut-off circuitry is activated, the Power Supply Charger will not

be able to successfully charge the battery. If this occurs, please contact Gold

Standard Phantoms. To avoid this from happening ensure that the Power Supply

is recharged after each use, and if not used for a long period of time, ensure that

it is checked and recharged every month.

7.3.2 QASPER-LINK WIRELESS INTERFACE The QASPER-LINK Wireless Interface is charged using the QASPER-LINK Wireless Interface Charger. To charge:

1. Plug the QASPER-LINK Wireless Interface Charger into a power outlet socket.

2. Plug the QASPER-LINK Wireless Interface Charger Cable USB connector into the socket in

the QASPER-LINK Wireless Interface Charger. 3. Plug the other end into the Power Socket on the QASPER-LINK Wireless Interface.

When power is supplied to the QASPER-LINK Wireless Interface, the ‘Power In LED will be lit. If

the battery is being charged, the Battery Charging LED will also be lit. Unlike the Power Supply,

the QASPER-LINK Wireless Interface can be switched on and used whilst being charged.

7.4 SEPARATING THE PUMP AND PERFUSION UNIT The Pump Unit’s aluminium enclosure ensures the necessary shielding from the high-power

radiofrequency transmissions generated by the MRI scanner, and ensures that no interference is

generated by the pump’s circuitry that would otherwise result in image artefacts. However,

because of its construction it is susceptible to coupling to the induction of eddy currents by the

MRI gradients, resulting in significant vibrations that can:

• Affect the flow measurement, resulting in over/underestimation of the flow rate.

• Cause motion/vibrations in the PLC, degrading image quality.

To prevent these problems, during MRI scanning the Pump Unit and Perfusion Unit should be

separated, and the Pump Unit moved to its full extent away from the Perfusion Unit. This is

achieved using the Base Split Mechanism, illustrated in Figure 28.

To separate the Pump Unit and Perfusion Unit: 1. Slide the lever towards the opposite side of the Phantom. The marker is red when the

latch is engaged, and white when the latch is disengaged (Figure 28.a)

2. Slide apart the Pump Unit and Perfusion Unit (Figure 28.b).

3. Manually feed the hoses through from the Perfusion Unit whilst separating the Pump Unit and Perfusion Unit until the tethers are pulled taught (Figure 28.c).


To join the Pump Unit and Perfusion Unit, the process is reversed:

1. Bring the Pump Unit and Perfusion Unit together whilst manually feeding the hoses back to

the Perfusion Unit. 2. Ensure that the base plates of the two parts are touching, and that the tethers are not

trapped in between.

3. Slide the lever back to its original position. This requires the latch to correctly engage with

the slots on the attachment bosses. Once locked the marker will be red.

It is recommended that this process is practised several times by each user of the QASPER

system.

CAUTION 7. Ensure that the base is correctly locked together before attempting

to lift the Phantom. Failure to do so could result in the two parts becoming

separated, potentially resulting the Phantom being dropped and damaged.

Figure 28: How to separate the Pump Unit and Perfusion Unit using the Base Split Mechanism

a.

c.

b.

Slide Lever

Latch engaged: marker red Latch disengaged: marker white

Slide bases apart

Extend until tethers are taught


7.5 AIR CLEARANCE

From time-to-time, bubbles may form in the perfusion chamber, as shown by the circled region in

the MRI image in Figure 29. This is quite normal and is a consequence of the porous material

become increasingly saturated with perfusate over time. It is advised to remove these from the

perfusion chamber, as they will lead to image artefacts. To do so, perform the following

procedure.

1. Separate the Perfusion Unit and Pump Unit (see section 7.4) so that the tethers are fully

taught.

2. Turn the pump on.

3. Tilt the Perfusion Unit so that the PLC is oriented vertically.

4. The bubbles will now be able to flow out of the perfusion chamber. Manually adjust the

inclination angle to help move the bubbles to the exit of the perfusion chamber.

The perfusion chamber should be checked visually for the presence of air/bubbles before each

scan session as they may affect the perfusion measurement.

7.6 QASPER PUMP CONTROL SOFTWARE The latest version of the QASPER Pump Control Software can be downloaded from

www.goldstandardphantoms.com/downloads. A user guide is included with the software, please

refer to this.

Figure 29: Presence of air in the perfusion chamber

https://www.goldstandardphantoms.com/downloads


8 USING THE QASPER SYSTEM FOR ASL QUALITY ASSURANCE MEASUREMENTS

Quality Assurance (QA) tests in MRI typically involves routine imaging of a test object (i.e.

phantom) with a consistent protocol. By keeping the test conditions as similar as possible each

time, differences due to changes in the imaging hardware can be detected.

Making QA measurements with the QASPER system follows this principle, and to perform the

most effective QA protocol it is useful to understand the sources of variability in the operation of

the QASPER system that attribute to variance in the ASL perfusion measurement.

The two main labelling strategies for ASL are detailed in Figure 30: pseudo-continuous ASL

(pCASL) and pulsed ASL (PASL). Both share similarities in that the inflow is labelled, creating a

bolus of defined temporal length (Label Duration for pCASL and TI1 for PASL with

QUIPPSS/Q2TIPS), and after a prescribed period of time an image is acquired, usually with a fast

acquisition technique such as EPI or 3D-GRASE. This is performed for both a label condition,

and a control (where no labelling takes place but all other parameters are the same), and then

these images are subtracted to obtain a perfusion weighted image, also known as ΔM. Because

the actual perfusion signal is of low SNR, multiple control/label pairs are acquired and then

averaged together.

The ΔM image has arbitrary units. For quantification, this must be divided by an image of the

equilibrium magnetisation, M0, that is obtained from the same acquisition, resulting in the

normalised ΔM:

Δ𝑀𝑁𝑜𝑟𝑚𝑎𝑙𝑖𝑠𝑒𝑑 =Δ𝑀

𝑀0

The normalised ΔM can then be fitted to a model for quantification of the perfusion rate. For more

information on the acquisition, processing and quantification of ASL, please see the 2015 ASL

White Paper: https://doi.org/10.1002/mrm.25197.

8.1 RECOMMENDED QASPER QA PROTOCOL QA requirements vary from site to site and study to study, however as a starting point we

recommend a protocol that is based around some ASL acquisitions at a few different QASPER

flow rates, and a few other scans that give some additional information about whether the

QASPER phantom is functioning correctly.

Figure 30: pCASL and PASL Labelling Strategies

https://doi.org/10.1002/mrm.25197


Scan Purpose QASPER State

ASL Assess perfusion measurements At each flow rate tested

M0 (if not part of the

ASL acquisition)

Acquire the equilibrium magnetisation

normalisation image

At each flow rate tested

Phase Contrast

Velocimetry in the

label chamber/tube.

Assess the velocity and actual flow rate

in the phantom system.

At each flow rate tested

TOF Assess the integrity of the flow path Flowing, at maximum flow rate

tested for maximum SNR.

T1 Map (optional) Assess the T1 of the perfusate Static

T2 Map (optional) Assess the filling of the porous material Static

Flow rates in the range of 200ml/min to 350ml/min provide a range of transit times and perfusion

rates. To determine a suitable ASL protocol we recommend starting with a protocol that is used

on patients/subjects and then adapting the field of view for the QASPER phantom (as it is

somewhat smaller than a head). QASPER was designed to have a similar transit time to that

found in humans, so labelling parameters do not need to be modified. If you require any

assistance in setting up a QA protocol please contact Gold Standard Phantoms directly –

[email protected].

8.2 QASPER QA ON GSP CLOUD QASPER comes with a subscription to GSP Cloud for cloud-based analysis of QASPER data for

quality assurance. An account for your organisation should have been set up when the phantom

was purchased. To use GSP Cloud, the DICOM files are uploaded as a zip archive, after which

automated processing takes place to calculate key QA metrics that can be tracked longitudinally.

GSP Cloud has an additional requirement for a QA protocol: one of the scans needs to be

‘synchronised’ with the QASPER Pump Control software. This is simply done by clicking the

‘synchronise’ button in the software when the scan starts. After uploaded data to GSP Cloud, the

user needs to indicate which of the acquisitions was synchronised. We recommend doing this for

either the scout/localiser, or the first ASL scan, however in practise it can be any scan. For more

information please view the QASPER Pump Control Software user manual.

8.3 SOURCES OF VARIABILITY The table below lists the most common sources of variation when using the QASPER phantom for

ASL QA. Note however that this is not an exhaustive list. It also assumes a single MRI scanner,

and that acquisition parameters (FOV, image matrix, TE, TR, etc) are kept consistent. Source Name Source Type Effect

Flow Rate Phantom operation

Shorter transit time, increased perfusion rate

Longer transit time, decreased perfusion

rate. Signal may remain in feeding tubes.

Temperature Phantom operation

Decreased viscosity of the perfusate,

minimal effect on flow in range 15-25C

Increased viscosity of the perfusate,

minimal effect on flow in the range 15-25C.

Below 15C the viscosity may be too great to

achieve the desired flow rate.

mailto:[email protected]


Label Plane Distance

from centre of FOV Label parameter

Label plane further away from centre of

FOV, transit time to porous material

increased, less signal dispersion for given

labelling parameters

Label plane closer to centre of FOV, transit

time to porous material decreased,

increased signal dispersion for given

labelling parameters.

Label Duration

(pCASL/CASL only) Label parameter

More labelled perfusate delivered to the

perfusion chamber, increased perfusion

signal, increased signal dispersion for given

Post Label Delay.

Less labelled perfusate delivered to the

perfusion chamber, decreased perfusion

signal, decreased signal dispersion for

given Post Label Delay.

Post Label Delay

(pCASL/CASL only) Label parameter


perfusion chamber, increased signal

dispersion.

< Transit time: Labelled perfusate remains in

the feeding tubes.

> Transit time: All labelled perfusate

delivered, wash in of unlabelled perfusate.


perfusion chamber, decreased signal

dispersion.

< Transit time: labelled perfusate remains in

the feeding tubes

Inversion Time/TI2

(PASL only) Label parameter



dispersion.



dispersion.

Bolus Duration/TI1

(PASL with

QUIPPSS/Q2TIPS only)

Label parameter



dispersion for given TI2.


perfusion chamber, decreased signal

dispersion for given TI2.

Note that for PASL, the labelled bolus of perfusate will only be completely delivered to the perfusion

chamber if TI2 – TI1 > Transit Time.

FOV Location and

alignment. Acquisition parameter

Partial volume effects in the porous material

will be inconsistent if this varies greatly.

8.4 EQUIPMENT SETUP For quality assurance measurements please set up the system as described in section 6.4. Care

should be taken to ensure that the phantom is positioned and aligned in a repeatable manner.

As each MRI scanner is different, in particular the relative heights of foam pads, RF coils etc on

the patient couch, it is recommended that some time is taken to establish the correct combination

of foam pads gives best results, and then this is documented with photographs as local standard


operating procedure. (SOP). Best results can be achieved by:

• Use large foam pads placed underneath the Pump Unit and Perfusion Unit so that the

Phantom is raised high enough to be able to go flat into the head coil.

• Support the ‘head’ end of the Phantom in the head coil with foam padding so that it

remains level. A small plastic spirit level can help here, but checking by eye is usually

sufficient.

• Use the laser crosshair marker to ensure that the PLC is square with the MRI scanner (see

Figure 31)

8.5 MRI SCAN PLANNING For robust and repeatable planning of ASL scans, the following should be adhered to:

Parameter Requirements

FOV Location Locate centre of FOV at the centre of the porous stack (see Figure 32),

between the third and fourth porous layers.

FOV Orientation Transverse slices, obliquely aligned with the porous stack if necessary.

FOV Size Ensure the FOV covers the entire perfusion chamber in the slice direction.

This is so that certain landmarks can be utilised for image registration.

Label Plane Location

(pCASL only)

Locate at a fixed offset from the centre of the FOV. There are fiducial

markers in the label chamber at 50mm, 60mm, 70mm, etc. to assist.

Other parameters should be standardised and kept the same for each QA measurement that is to

be compared longitudinally (i.e. so that apples can be compared with apples).

The crosshair of

the laser marker

should be

located here

The axial laser

line should cross

here

Figure 31: Standardised alignment of the QASPER phantom in a MRI scanner


Centre of porous

stack (CoS) Place centre of FOV

Ensure FOV

covers entire

perfusion chamber

pCASL labelling

slab

Interface

between layers

3 and 4

Figure 32: FOV Placement.


9 MR CONDITIONAL STATEMENTS The following components of the QASPER system are defined as MR

Conditional. In all cases testing was performed on Siemens

Trio/Verio/Skyra/Prisma 3T, Philips Ingenia/Achieva 3T, GE Discovery

MR750/Signa/PETMR 3T.

All other components should be considered MR unsafe and MUST NOT BE BROUGHT INTO THE

MR ENVIRONMENT.

9.1 GSP 1006 PHANTOM The GSP 1006 Phantom can be safely scanned under the following conditions:

• The pump should be disengaged and positioned so that the tethers are fully extended

• Static magnetic field of up to 7 Tesla.

• Spatial gradient field of up to 80mT/m

• Maximum whole body averaged SAR of 2 W/kg for 15 minutes of scanning.

• Using the correct cable trap for the MRI scanner.

9.2 GSP 1005 POWER SUPPLY The GSP 1005 Power Supply can be safely used in the MR environment under the following

conditions:

• The magnetic field alarm is silent. This alarm will sound when a static magnetic field is

32mT or greater.

• The power supply should be located well away from the magnet, on the ground and off-

axis from the magnet.

• The Power Supply contains a steel-cased battery and so poses a projectile hazard.

• DO NOT BRING THE POWER SUPPLY CLOSER TO THE MAGNET THAN THE POINT AT

WHICH THE ALARM SOUNDS.

9.3 TUNED CONNECTION CABLE During MRI scanning, the QASPER system must only be used with the correct cable trap for that

MRI scanner. The cable trap end of the cable connects to the phantom, and the long end of the

cable connects to the power supply; each end uses a different connector so the cable can only

be connected in one orientation.

9.4 GSP 1008 QASPER-LINK WIRELESS INTERFACE The GSP 1008 QASPER-LINK Wireless Interface can be safely used in the MR environment under

the following conditions:

• It should be placed around the edge of the scan room, close to a waveguide, and in direct

sight of the patient end of the bore of the MRI scanner.

• It can be brought as close to the magnet as the Power Supply; there is no alarm to

indicate the ambient magnetic field, however this device does not pose a projectile

hazard.

9.5 GSP 1019 FIBRE OPTIC CABLE This fibre optic cable should be passed through a waveguide and connects to the Bluetooth

Transceiver. The fibre optic connectors have stainless steel crimp rings, which are weakly

magnetic and so the cable should be kept at the edge of the scan room.

QASPER: INSTRUCTIONS FOR USE · Imaging (MRI). It is a calibration standard for MRI based perfusion measurements using ASL. It simulates the process of delivery of arterial blood

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